1. Field of the Invention
This invention relates generally to portable rescue tools and, more particularly, to a jaw constructed for use with such rescue tools. Rescue tools of the indicated type are well known and are used for aiding in the rescue of accident victims trapped in the wreckage of an automobile, an airplane or the like. One well known type of rescue tools are those of the "JAWS OF LIFE" rescue system manufactured by Hale Fire Pump Company.
2. Description of the Prior Art
Typical of the rescue tools in use today are those described in U.S. Pat. No. 3,819,153 which discloses a fluid-powered rescue tool utilizing a base and a pair of force arms to supply a high magnitude push-pull force for removing occupants from wreckages and for separating wreckages of automobiles or the like which have become entangled together. One type of rescue tool disclosed in said patent is known in the art as a spreading tool. Spreading tools are used in rescue or other types of operations to pry, bend, spread, pull and lift a structure during a rescue or other type of operation. Examples of specific applications of spreading tools are (1) a condition where it is necessary to spread a damaged windowframe of a wrecked automobile to gain access to the automobile or providing a way that an injured person can be removed through the window opening, (2) a condition where it is necessary to move a seat in a damaged automobile, (3) a condition where it is necessary to raise a collapsed dashboard of a wrecked automobile, and (4) a condition where it is necessary to raise the collapsed steering column of an automobile. In the last-mentioned example it is often difficult to position the rescue tool so that the tip of one of the force arms will engage the steering column without sliding.
The spreading tools in use today comprise field replaceable tips or jaws which are mounted on the end of the force arm. The jaws are adapted to contact or engage the part to be spread at a work engaging surface of the jaw, which surface is provided with a plurality of teeth. In the jaws in use today these teeth are formed of shallow serrations extending throughout the work engaging surface in an evenly spaced arrangement. Because of the shallowness, orientation, configuration and arrangement of the teeth on the prior art jaws, in some applications difficulty has been encountered in maintaining engagement between the work engaging surfaces of the jaws and the part to be spread. This failure to maintain engagement becomes most serious when the force arms are spread apart a substantial amount at the end of the spreading cycle. The jaws of the prior art have a tendency, in some applications, to skip out and jump back at the operator and also to slip along the material being worked on by the jaws. Also, in some applications, particularly when the jaws are spread apart a substantial amount, the tool may actually jump into the car and endanger an occupant thereof. Further, the jaws of the prior art present problems in maintaining engagement with a steering column during an operation in which the steering column is lifted away from the driver. While the serrated type of construction of the prior art is designed to secure the jaws to the work area, a problem develops as the spreading of the jaws increases because the material being worked on often bends and forces itself away from the shallow serrations of the prior art jaw thereby resulting in a slipping of the jaw relative to the material being worked on by the jaw.